MjGoLogger

A Go library for file-based logging with multiple severity levels and automatic caller information.

Features

• Multiple log levels: Info, Debug, Warn, Error
• Automatic caller information (file and line number)
• File-based logging with timestamps
• Simple setup and teardown

Installation

go get github.com/mjbmarques/MjGoLogger

Usage

Basic Example

package main

import "github.com/mjbmarques/MjGoLogger"

func main() {
    // Setup logger with a log file
    mjgologger.Setup("app.log")
    defer mjgologger.Stop()

    // Log messages at different levels
    mjgologger.Info("Application started")
    mjgologger.Debug("Debug information: %s", "some value")
    mjgologger.Warn("This is a warning")
    mjgologger.Error("An error occurred: %v", err)
}

API Reference

Setup

Initializes the logger with the specified log file. Must be called before using any logging functions.

func Setup(fileName string)

Parameters:

• fileName: Path to the log file to create/write to

Example:

mjgologger.Setup("logs/app.log")

Stop

Closes the log file. Should be called when logging is complete (typically with defer).

func Stop()

Example:

mjgologger.Setup("app.log")
defer mjgologger.Stop()

Info

Logs an informational message with [INFO] severity level.

func Info(msg string, args ...any)

Parameters:

• msg: Message format string
• args: Optional arguments for string formatting

Example:

mjgologger.Info("User %s logged in", username)

Debug

Logs a debug message with [DEBUG] severity level.

func Debug(msg string, args ...any)

Parameters:

• msg: Message format string
• args: Optional arguments for string formatting

Example:

mjgologger.Debug("Variable value: %v", someVar)

Warn

Logs a warning message with [WARN] severity level.

func Warn(msg string, args ...any)

Parameters:

• msg: Message format string
• args: Optional arguments for string formatting

Example:

mjgologger.Warn("Connection timeout, retrying...")

Error

Logs an error message with [ERROR] severity level.

func Error(msg string, args ...any)

Parameters:

• msg: Message format string
• args: Optional arguments for string formatting

Example:

mjgologger.Error("Failed to connect: %v", err)

Log Format

Each log entry includes:

• Timestamp (date and time)
• Severity level ([INFO], [DEBUG], [WARN], [ERROR])
• Caller information (file path and line number)
• Log message

Example log output:

2025/12/03 15:04:05 [INFO][/path/to/file.go:42]: Application started
2025/12/03 15:04:06 [DEBUG][/path/to/file.go:43]: Processing request ID: 12345
2025/12/03 15:04:07 [WARN][/path/to/file.go:44]: Cache miss for key: user_data
2025/12/03 15:04:08 [ERROR][/path/to/file.go:45]: Database connection failed

License

See LICENSE file for details.